Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Explain indications for surgery in aortic aneurysm, Explain Indications for...

Explain Indications for Surgery in Aortic Aneurysm? Indications for Surgery :  Thoracic aortic aneurysms are classified by the portion of aorta involved - ascending, arch,

Sexual reproduction, SEXUA L REPRODUCTION 1 .       Amphigony       ...

SEXUA L REPRODUCTION 1 .       Amphigony        -          Zygote is formed. (i) Syngamy Fusion of gametes. (a) Endogamy - It involves self fertilisation. e.g.

Prevention and control of water pollution, Various ways/techniques suggeste...

Various ways/techniques suggested for control of water pollution are as follows: 1. Pollutants (radio active, chemical, biological) present in water bodies can be removed by app

Explain wound healing and formation of woven bone, Wound healing and format...

Wound healing and formation of woven bone Stage 1: Wound healing and formation of woven bone (callus) (2 to 6 weeks) The ability of the body to respond to the "trauma" indu

Define the activation of an agonist during movement, Explain the relationsh...

Explain the relationship between an agonist muscle and its antagonist as it relates to positional control, functional movement and neuromuscular activation. For example, how the th

Reproductive cycle - human development, Reproductive Cycle The whole r...

Reproductive Cycle The whole reproductive cycle consists of an ovarian cycle and a uterine cycle. Figure illustrates one complete reproductive cycle. You can observe in the fi

Zoonoses disease-ehrlichiosis, Ehrlichiosis The disease is caused by a ric...

Ehrlichiosis The disease is caused by a rickettisia, called Ehrlichia canis. Dogs and man are the reservoir hosts. The infection is transmitted through bite of infected tick, Rhip

What is diffusion, Diffusion is the spreading of substance molecules from a...

Diffusion is the spreading of substance molecules from a region where the substance is more concentrated to other region where it is less concentrated. For example, during the boil

Explain the properties locust bean gum, Explain the Properties Locust bean ...

Explain the Properties Locust bean gum Locust bean gum is slightly soluble in room temperature water and must be heated to 75 to 85 o C for complete hydration and viscosity dev

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd